Submission #569579

#	Time	Username	Problem	Language	Result	Execution time	Memory
569579		hoanghq2004	Hexagonal Territory (APIO21_hexagon)	C++14	30 / 100	51 ms	8556 KiB

hexagon

#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include "hexagon.h"

using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;

const int mod = 1e9 + 7;
const int N = 2e5 + 10;

struct Vector {
    long long x, y;
    Vector operator - (const Vector& other) const {
        return {x - other.x, y - other.y};
    }
    long long operator * (const Vector& other) const {
        return x * other.y - y * other.x;
    }
} P[N];

int dx[6] = {0, 1, 1, 0, -1, -1};
int dy[6] = {1, 1, 0, -1, -1, 0};

int power(int a, int n) {
    int ans = 1;
    for (; n; n >>= 1, a = 1LL * a * a % mod)
        if (n & 1) ans = 1LL * ans * a % mod;
    return ans;
}

int draw_territory(int N, int A, int B, vector<int> D, vector<int> L) {
    vector <Vector> P = {{0, 0}};
    long long x = 0, y = 0, b = 0;
    for (int i = 0; i < N; ++i) {
        --D[i];
        x += L[i] * dx[D[i]];
        y += L[i] * dy[D[i]];
//        x = (0LL + x + L[i] * dx[D[i]] + mod) % mod;
//        y = (0LL + y + L[i] * dy[D[i]] + mod) % mod;
        b = (b + L[i]) % mod;
        P.push_back({x, y});
    }
    long long S = 0;
    for (int i = 1; i < P.size(); ++i) S += P[i - 1] * P[i];
//    for (int i = 1; i < P.size(); ++i) S = (S + P[i - 1] * P[i]) % mod;
    S = abs(S);
    S %= mod;
    long long i = ((1LL * (S - b + 2 + mod) * power(2, mod - 2)) + b) % mod;
    return i * A % mod;
}

//
//int main() {
//  int N, A, B;
//  assert(3 == scanf("%d %d %d", &N, &A, &B));
//  std::vector<int> D(N), L(N);
//  for (int i = 0; i < N; ++i) {
//    assert(2 == scanf("%d %d", &D[i], &L[i]));
//  }
//
//  int result = draw_territory(N, A, B, D, L);
//  printf("%d\n", result);
//  return 0;
//}
//
//

Compilation message (stderr)

hexagon.cpp: In function 'int draw_territory(int, int, int, std::vector<int>, std::vector<int>)':
hexagon.cpp:50:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Vector>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |     for (int i = 1; i < P.size(); ++i) S += P[i - 1] * P[i];
      |                     ~~^~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 0 / 6
• Subtask 3: 0 / 11
• Subtask 4: 12 / 12
• Subtask 5: 15 / 15
• Subtask 6: 0 / 19
• Subtask 7: 0 / 18
• Subtask 8: 0 / 16